Oncosclera navicella ( Carter, 1881 )

Nicacio, Gilberto & Pinheiro, Ulisses, 2015, Biodiversity of freshwater sponges (Porifera: Spongillina) from northeast Brazil: new species and notes on systematics, Zootaxa 3981 (2), pp. 220-240 : 223-224

Oncosclera navicella ( Carter, 1881)

( Figure 3 )

Spongilla navicella, Bonetto & Ezcurra 1964: 247 , Bonetto & Ezcurra de Drago 1970: 45. For other synonyms see Muricy et al. (2011).

Material studied. UFPEPOR1117 (in part), 1118 (in part), 1133 (in part), 1134 (in part), São Francisco River (III), Usina Hidrelétrica Luiz Gonzaga, Petrolândia, Pernambuco, Brazil, 09°08'37.1"S 38°17'48.9"W, coll. E.L.R. Lima, 19.v.2010.

General morphology. Encrusting sponge, circular, beige in colour ( Fig. 3 a). Surface hispid. Spicules. Megascleres (204–360/12–21µm) straight to slightly curved smooth oxeas ( Fig. 3 b). Microscleres absent. Gemmuloscleres microspined oxeas (63–141/12–15µm), stout, curved, boomerang-shaped ( Fig. 3 c). Gemmules are hemispherical raging 432–480µm in diamenter; gemmuloscleres are embedded tangentially.

Distribution. Brazil ( Muricy et al. 2011); Argentina, Uruguay and Venezuela ( Bonetto & Ezcurra 1964, Ezcurra de Drago & Bonetto 1969, Tavares & Volkmer-Ribeiro 1997).

Remarks. Records of Oncosclera navicella have been made from wide-ranging localities in South America, especially in Brazil where this species is widespread in all regions. The specimens investigated here have remarkable differences in range of dimension of megascleres when we compared those with previous studies ( Volkmer-Ribeiro 1970). This has already been observed in Amazon specimens with minute size, which has been described with smaller megascleres in comparison with largest specimens collected in Paraná River, south Brazil ( Tavares & Volkmer-Ribeiro 1997).

Figures

FIGURE 3. Oncosclera navicella: (a) UFPEPOR 1117 specimen; (b) megasclere; (c) gemmulosclere. Scale bars: a— 1 cm; b— 90 µm; c— 30 µm.